The role of biotin as the prosthetic group of carboxylases and transcarboxylase has been recognized. Various cell culture studies suggest a function for biotin other than as the prosthetic group of the carboxylases. The successful treatment of some organic acidemias perinatally with large doses of biotin has renewed interest in the study of biotin-dependent carboxylases. The role of biotin in the lesion development is being investigated. That a simple deficiency of biotin can occur under conditions like total parenteral alimentation has been pointed out. Yet, there is no consensus about the daily requirement of biotin for humans. Apart from the neonatal condition referred to above, there is much concern in establishing criteria to assess the biotin status of groups at risk in the general population. The inadequate supply of biotin to farm animals can have serious economic consequences. The contribution of intestinally synthesized biotin to the biotin supply of monogastric animals seems to be negligible. Deficiency of biotin in poultry results in a fatty liver and kidney syndrome which has features in common with the sudden infant death syndrome. The immediate goal of this conference is to provide a forum for direct communication among biochemists, nutritionists and clinicians. The critical evaluation of the existing knowledge will help in identifying unresolved problems and thus establish the directions for further research related to biotin. In order to facilitate direct communications among various groups of scientists participating in the conference, the morning sessions are devoted to biochemical problems and the afternoon sessionss to clinical or animal nutrition studies.